English verb conjugation
COULD UNDERHEAT

Regular verb: underheat - underheated - underheated

Affirmation

Simple form	V-ing form
I could underheat you could underheat he could underheat we could underheat you could underheat they could underheat	I could be underheating you could be underheating he could be underheating we could be underheating you could be underheating they could be underheating
Perfect	V-ing perfect
I could have underheated you could have underheated he could have underheated we could have underheated you could have underheated they could have underheated	I could have been underheating you could have been underheating he could have been underheating we could have been underheating you could have been underheating they could have been underheating

Negation

Simple form	V-ing form
I couldn't underheat you couldn't underheat he couldn't underheat we couldn't underheat you couldn't underheat they couldn't underheat	I couldn't be underheating you couldn't be underheating he couldn't be underheating we couldn't be underheating you couldn't be underheating they couldn't be underheating
Perfect	V-ing perfect
I couldn't have underheated you couldn't have underheated he couldn't have underheated we couldn't have underheated you couldn't have underheated they couldn't have underheated	I couldn't have been underheating you couldn't have been underheating he couldn't have been underheating we couldn't have been underheating you couldn't have been underheating they couldn't have been underheating

Interrogative form

Simple form	V-ing form
could I underheat? could you underheat? could he underheat? could we underheat? could you underheat? could they underheat?	could I be underheating? could you be underheating? could he be underheating? could we be underheating? could you be underheating? could they be underheating?
Perfect	V-ing perfect
could I have underheated? could you have underheated? could he have underheated? could we have underheated? could you have underheated? could they have underheated?	could I have been underheating? could you have been underheating? could he have been underheating? could we have been underheating? could you have been underheating? could they have been underheating?

Interro-negative form

Simple form	V-ing form
couldn't I underheat? couldn't you underheat? couldn't he underheat? couldn't we underheat? couldn't you underheat? couldn't they underheat?	couldn't I be underheating? couldn't you be underheating? couldn't he be underheating? couldn't we be underheating? couldn't you be underheating? couldn't they be underheating?
Perfect	V-ing perfect
couldn't I have underheated? couldn't you have underheated? couldn't he have underheated? couldn't we have underheated? couldn't you have underheated? couldn't they have underheated?	couldn't I have been underheating? couldn't you have been underheating? couldn't he have been underheating? couldn't we have been underheating? couldn't you have been underheating? couldn't they have been underheating?